The disclosed invention relates to means for detecting and measuring ferrous particles in a fluid medium, and it is of particular use for detecting ferrous particles in the lubricant of an engine or mechanical transmission. In such an application, the monitoring of such particles may be utilized to give warning of malfunction or other mechanical breakdown of the engine or transmission. The invention disclosed is of particular importance for the operation of an internal combustion engine, especially highly stressed helicopter and aircraft engines wherein prior warning of a malfunction permits corrective action prior to catastrophic failure.
Metal parts in the internal combustion or mechanical transmission, e.g., gear boxes, undergo wear because of friction between the metallic parts or a metal part and a non-metal part. The result of the wearing friction is metallic contamination of the lubricant or transmission fluid. The contamination comprises metal particles of many sizes and shapes. Monitoring of the metal particles contained in the fluid can provide early warning of the deterioration of a mechanical device such as the internal combustion engine or its associated operating systems such as mechanical power transmissions or other gear boxes.